Targeted, community-based strategies — as opposed to total shutdowns — can still help stop the COVID-19 coronavirus epidemic, but only if accompanied by widespread, aggressive testing efforts.
At a Monday press briefing, President Trump bemoaned, “our country was not meant to be shut down,” and announced plans “to allow local economies to cautiously resume activity” in a matter of weeks, not months.
This, combined with other statements from experts, seemed to signify the desire to shift back to the more localized strategy of contact tracing, isolation, and quarantine similar to CDC protocol in the earliest stages of the U.S. outbreak when cases came from returning travelers from China.
But as Julie Fischer, PhD, of Georgetown University in Washington, D.C., told MedPage Today, that has to be accompanied by widespread testing efforts. Three weeks ago, the U.S. had tested fewer than 1,000 people, she noted. About 325,000 have now been tested.
“Testing was slow to come online” here, she said. “We didn’t know the extent of community transmission until cases had begun to climb quickly in those areas with the earliest introduction of disease.”
The slow roll-out of diagnostic testing and widespread community spread, as well as the fact that asymptomatic individuals may be playing a large role in transmission, means good data about this outbreak in the U.S. is largely hard to come by.
Still, Fischer emphasized the importance of “pressing forward and testing the population aggressively” for a number of reasons.
From an analytical perspective, there is no way to determine the case-fatality rate for COVID-19 since we don’t know the number of cases without testing, Fischer noted. A case-fatality rate helps shed light on who is at risk, and data from China helped us to understand the population most susceptible to getting severe disease.
“Because we don’t have good data on the number of confirmed cases, we’re working a little bit in the dark. Without understanding case-fatality rates accurately,” it is more difficult to effectively prioritize where to use resources, Fischer said.
Not only that, widespread testing is essential in order to curb population-wide interventions, such as closing all non-essential businesses, to slow the spread of disease, with “profound implications for the economy, lives and livelihoods.”
“If we had widespread, aggressive diagnostic testing, we can see where we truly have community transmission, and where there is still the possibility of containment,” Fischer said.
“We still have lots of communities in the U.S. where infection may not be that widespread, and we may be able to use public health tools and case-based interventions to focus priorities on people who have been infected and exposed to disease, and focus on keeping those people away from vulnerable populations,” she noted.
In order to do that, communities not only need to test symptomatic people, but start testing “a representative percentage of the population” who are asymptomatic, similar to what happened in South Korea and Singapore, to get an idea about how widespread community transmission is.
She cited statistics stating as of last Tuesday, South Korea had carried out 5,200 tests per million inhabitants, while the U.S. at that point had only performed 74 tests per million.
Once wide-scale diagnostic testing is in place, ideally outside of healthcare facilities, the U.S. theoretically could pinpoint places “where we have to keep up population-wide intervention and where there is an opportunity to do case-based interventions,” Fischer noted.
Otherwise, these more focused assessments are more often seen at both the beginning and end of outbreaks, to “mop up the remaining cases” in pockets where there are still disease.